Manhole grade ring

ABSTRACT

Several improved manhole grade rings and methods for providing improved manhole grade rings. In one embodiment, a plurality of concentric annular rings are connected by radial ribs. Certain radial ribs can be broken to provide a manhole grade ring of the desired diameter. In several other embodiments, concentric annular ribs and interconnecting radial ribs provide lightweight stackable manhole grade rings. In another embodiment, a manhole grade ring defines an annular cavity that can be filled to reinforce the manhole grade ring. Two embodiments provide improved forms for pouring manhole grade rings in place. One form provides a plurality of forms of different diameters that can be filled to any height, while another form provides adjustable height of the manhole grade ring.

This application claims priority to U.S. Provisional Application Ser. Nos. 60/909,749, 60/909,752, and 60/909,754, all filed Apr. 3, 2007.

BACKGROUND

The present invention relates to manhole grade rings, which are used in the construction and rehabilitation of manhole access points.

A manhole chimney is the vertical extension off of the horizontal sewer pipe. The manhole chimney may include a base, a manhole cone, a grade ring and a manhole frame with a cover. The manhole chimney may also include risers, transition sections, etc. All products mentioned except for the manhole frame and cover are buried under the surface grade.

The grade rings are installed on top of a manhole cone in order to raise the manhole chimney level with the surface grade. The top installed ring will need to support a steel manhole frame, which the manhole cover sits within. The manhole grade ring when stacked needs to be water and gas tight and sealed to the cone and the frame to prevent water and gas leakage and infiltration. When properly installed, the manhole grade rings have to be able to withstand travel of vehicles weighing 40,000 lbs/axle.

The grade rings are typically pre-formed concrete rings. The concrete grade rings are heavy and cumbersome, and various sizes need to be stored and brought to the work site, so that the proper diameter and height will be available.

SUMMARY

The present invention provides several improved manhole grade rings and methods for providing improved manhole grade rings.

In one embodiment, a plurality of concentric annular rings are connected by radial ribs. Certain radial ribs can be broken to provide a manhole grade ring of the desired diameter. In several other embodiments, concentric annular ribs and interconnecting radial ribs provide lightweight stackable manhole grade rings. In another embodiment, a manhole grade ring defines an annular cavity that can be filled to reinforce the manhole grade ring.

Two embodiments provide improved forms for pouring manhole grade rings in place. One form provides a plurality of forms of different diameters, while the other form provides adjustable height of the manhole grade ring.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the application can be best understood from the following specification and drawings, the following of which is a brief description.

FIG. 1 is a side view of a manhole chimney including a manhole grade ring according to the present invention.

FIG. 2 is a top view of a manhole grade ring according to a first embodiment that could be used as the manhole grade ring of FIG. 1.

FIG. 3 is a perspective view of the manhole grade ring of FIG. 2.

FIG. 4 is a perspective view of manhole grade ring according to a second embodiment that could be used as the manhole grade ring of FIG. 1.

FIG. 5 is a perspective view of a manhole grade ring form that could be used to make a manhole grade ring to be used in FIG. 1.

FIG. 6 is a perspective view of the manhole grade ring form of FIG. 5 in a different position.

FIG. 7 is a perspective view of a stack of manhole grade rings according to a fourth embodiment, partially broken away.

FIG. 8 is an exploded view of the manhole grade rings of FIG. 7.

FIG. 8A is a bottom perspective view of the manhole grade rings of FIG. 8.

FIG. 9 is a perspective view of a stack of manhole grade rings according to a fifth embodiment, partially broken away.

FIG. 10 is an exploded view of the manhole grade rings of FIG. 9.

FIG. 11 is a perspective view of a stack of manhole grade rings according to a sixth embodiment, partially broken away.

FIG. 12 is an exploded view of the manhole grade rings of FIG. 11.

FIG. 13 is a perspective view of a manhole grade ring form according to a seventh embodiment.

FIG. 14 is a perspective view of the base of FIG. 13.

FIG. 15 is the form of FIG. 13 in a first position.

FIG. 16 is the form of FIG. 15 in a second position with a manhole frame situated thereon.

DESCRIPTION OF THE PRESENT INVENTION

FIG. 1 generically illustrates a manhole chimney 5. A manhole chimney 5 is the vertical extension off of a horizontal sewer pipe 6. The manhole chimney 5 may include a base 7, a manhole cone 8, a manhole grade ring 18 and a manhole frame 20 with a cover 9. The manhole chimney 5 may also include risers, transition sections, etc. (not shown). The manhole chimney 5 except for the manhole frame 20 and cover 9 are buried under the surface grade. The present invention provides several variations of manhole grade ring 18 or ways of making a manhole grade ring 18 that could be used in the manhole chimney 5 of FIG. 1.

A plastic manhole grade ring 18 a shown in FIGS. 2 and 3 is intended to be an all-inclusive design that contains grade rings A, B, C, D of all possible sizes, having, for example, the following inside diameters: 24″, 27″, 30″, and 36″. The grade rings A, B, C, D, could be used separately or in combinations of adjacent rings A, B, C, D, as appropriate. In the manufacturing process, all sizes are produced at one time in one injection mold. The grade ring includes a plurality of concentric grade rings A, B, C, D connected by radial ribs 34, 36, 38. The rings A, B, C, D include vertical circumferential ribs 12, 14, 16, 18, etc. some of which are connected by upper horizontal rings 30, 32, 33, 35 and some of which are connected only by the radial ribs 34, 36, 38. Two of the vertical circumferential ribs 12, 14 are connected by a lower horizontal ring 31. Cylindrical ribs 24, 26, etc. increase the strength of the rings A, B, C, D.

Depending on which size the user needs, he can pop out the interior rings by cutting or breaking the appropriate radial ribs at the work site to accommodate the accurate diameter. If the diameter is small, the user has the option to pop off the exterior ring and use it on other applications where a larger diameter is needed. Multiple rings can stack to achieve the appropriate height. In use, dirt, sand and rocks will fill the gaps between the vertical ribs 12, 14, 16, 18, etc. and below the horizontal rings 30, 32, 33, 35. The selected ring(s) would then be used as a manhole grade ring 18 in a manhole chimney 5, such as shown in FIG. 1.

A rotationally molded or blow molded grade ring 18 b is shown in FIG. 4. The grade ring 18 b includes a hollow annular cavity defined by annular upper, lower, inner and outer walls. An opening 44 to the annular cavity is provided for filling the annular cavity with a weighted substance like sand, dirt, rocks, concrete, etc. to provide strength. The opening 44 may have a threaded protruding neck 46, as illustrated, that can be closed by a complementary threaded cap 48. Varying diameters of the grade ring 18 b would be provided so that the proper diameter can be selected. Multiple grade rings 18 b could be stacked to achieve the appropriate height. The manhole grade ring 18 b would be used as a manhole grade ring 18 in a manhole chimney 5, such as shown in FIG. 1

A cast in place, concrete form 50 is shown in FIGS. 5 and 6. This form 50 assists in the pouring of concrete around the manhole. There is a center axis 52 about which all needed diameter forms 54, 56, 58 rotate. Depending on the diameter of the manhole, selected ones of the forms 54, 56, 58 are rotated to provide the appropriate inner diameter, such that the needed diameter 54, 56, 58 is the only size breaking the plane between the street and the ground. The remainder of the forms 54, 56, 58 stick above the surface. The forms 54, 56, 58 are plastic that is flexible enough to bend so that they can be rotated past one another. The flat ribbed handles 60 that protrude outwardly of the forms 54, 56, 58 are designed to sit on top of the existing street. This helps level the form 50. The selected form 54, 56 or 58 is inserted inside the cone 8 (for example, FIG. 1). The closer the cone 8 is to the surface, the more of the form will extend into the cone 8. Thus, the forms can be used for any necessary height. Then concrete is poured between the selected form 54, 56, 58 and the outer wall 62 to the desired height. The handles 60 will automatically place the form 50 at the angle of the surface level and the concrete can be leveled or angled inside the form 50. Once the concrete has begun to cure, the form 50 is removed. The cured concrete forms the manhole grade ring 18 of FIG. 1.

FIGS. 7, 8 and 8A illustrate a stack 70 of manhole grade rings 72, 72A, 72B, 72C according to a fourth embodiment. The grade rings 72A, B, C are simply different height versions of the grade ring 72, and are otherwise identical. The manhole grade rings 72 are each injection molded plastic as a single piece. Each grade ring 72 includes an outer annular wall 74 and an upper annular wall 76. A mid-annular wall 78 extends downwardly from an inner periphery of the upper annular wall 76. An inner annular wall 80 is connected to the mid-annular wall 78 by a plurality of radially extending ribs 82. A plurality of openings is formed through upper annular wall 76. The inner annular wall 80 includes a lip 84 that is offset inwardly and extends downwardly from the inner annular wall 80. The lip 84 mates with the inner annular wall 80 of a similar grade ring 72 stacked therebelow. An O-ring seal 86 or other type of seal 86 is secured to the upper most edge of the inner annular wall 80 and is received in a small channel behind the lip 84 of the grade ring 72 above. An annular cap 88, also having the lip 849 and fill-openings 77, may be stacked on the top grade ring 72C below the manhole frame 20. In use, any of the grade rings 72, 72A-C, alone or in combination, could be used to achieve a particular needed height at a worksite.

Referring to FIG. 8A, a lower horizontal annular wall 79 connects the inner annular wall 80 to the mid annular wall 78. Radial ribs 75 connect the mid annular wall 78 to the outer annular wall 74.

FIGS. 9 and 10 illustrate a stack 90 of a plurality of manhole grade rings 92, 92A, 92B, 92C according to a fifth embodiment. The manhole grade rings 92 are each injection molded plastic as a single piece. Each manhole grade ring 92 includes an outer annular wall 94, upper annular wall 96, mid-annular wall 98 and inner annular wall 100. The mid-annular wall 98 and inner annular wall 100 are connected by radially extending ribs 102. As in the previous embodiment, a lower horizontal annular wall (not visible) connects the inner annular wall 100 to the mid annular wall 98. Radial ribs 95 connect the mid annular wall 98 to the outer annular wall 94. Fill-holes 97 are formed through the intersection of upper annular wall 96 and outer annular wall 94. This allows dirt or concrete to flow into the annular cavity defined between the outer annular wall 94 and the mid-annular wall 98. O-ring or other seals 106 are secured to the upper most edges of the inner annular walls 100 to be received in channels defined behind lips 104 of above grade rings 92. An annular cap 108, also having the lip 109 and fill-openings 107, may be stacked on the top grade ring 92C below the manhole frame 20. In use, any of the grade rings 92, 92A-C, alone or in combination, could be used to achieve a particular needed height at a worksite.

FIGS. 11 and 12 illustrate a stack 110 of a plurality of manhole grade rings 112 according to a sixth embodiment. Each manhole grade ring 112 includes an upper annular wall 116 and a lower annular wall 115 connected by mid-annular wall 118 and ribs 119. An inner annular wall 120 is connected to the mid-annular wall 118 by a plurality of ribs 122. A lower horizontal annular wall 119 connects the inner annular wall 120 to the mid annular wall 118. Openings 117 are formed through the upper annular wall 116. A channel 127 is formed in the lower annular wall 115 for mating with an O-ring or other seal 126 on the upper annular wall 116 of a below grade ring 112. Caulk or other sealer could also be used instead of the seal 126. This grade ring 112 provides two large flat mating surfaces, i.e. lower annular wall 115 and upper annular 116, that facilitate sealing. Dirt or concrete will readily fill the open recesses between the upper annular wall 116 and lower annular wall 115 between the ribs 119. Again, a cap 128 is provided on the upper most grade ring 112C to support the manhole frame 20.

A concrete frame 130 for providing a manhole grade ring according to a seventh embodiment is shown in FIG. 13-16. Referring to FIG. 13, the form 130 includes a base 132 and an adjustable portion 134. The adjustable portion 134 includes a horizontal annular upper wall 136 integrally molded with (or subsequently attached to) an inner annular vertical wall 138. The inner annular vertical wall 138 continues upwardly above the upper wall 136 to form a small lip 137 to facilitate placement of a manhole frame 20 (FIG. 16). Bolts 140 are connected to the upper annular wall 136 and rest on the base 132. The bolts 140 can simply rest on the base 132 to provide an adjustable height for the adjustable portion 134.

FIG. 14 illustrates the base 132. The base 132 includes an inner annular ring 148 that is generally contained in a single plane. The base 132 further includes an outer annular ring 150 having circumferentially alternating peaks 152 and valleys 154. The valleys 154 are generally coplanar with the inner annular ring 148, while the peaks 152 are spaced upward from the plane by tapered ribs 156. Smaller ribs reinforce the base 132 between peaks 152 and taper away from the inner annular ring 148. A generally planar portion 160 connects the inner annular ring 148 to the outer annular ring 150. Generally triangular portions 162 connect the peaks 152 to the planar portion 160. Apertures 166 are formed through the planar portion 160.

In use, referring to FIG. 15, the adjustable portion 134 is placed on the base 132 with the bolts 140 resting in valleys 154 of the base 132. By turning the bolts 140, the height of the adjustable portion 134 can be adjusted to provide a desired height of a manhole frame 20, as shown in FIG. 16. Caulk or other sealant may be placed between the upper wall 136 of the adjustable portion 134 and the manhole frame 20. The area between the adjustable portion 134 and the base 132 is then filled with concrete. Weep holes 139 in the inner annular wall 138 allow air to escape from the annular cavity between the base 132 and adjustable portion 134. Slight flow of concrete from the weep holes 139 indicates that sufficient concrete is present between the base 132 and adjustable portion 134. When concrete cures, the base 132, adjustable portion 134 and concrete form a manhole grade ring 18 as shown in FIG. 1.

In accordance with the provisions of the patent statutes and jurisprudence, exemplary configurations described above are considered to represent a preferred embodiment of the invention. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. 

1) An adjustable plastic manhole grade ring comprising: a plurality of concentric annular vertical ribs including a first pair of annular vertical ribs and a second pair of annular vertical ribs; a first horizontal annular wall connecting the first pair of annular vertical ribs to one another; and a plurality of radial ribs connecting the first pair of annular vertical ribs to the second pair of annular vertical ribs. 2) The adjustable plastic manhole grade ring of claim 1 further including a second horizontal annular wall connecting the second pair of annular vertical ribs to one another. 3) The adjustable plastic manhole grade ring of claim 1 further including first cylindrical ribs reinforcing the first horizontal wall. 4) A plastic manhole grade ring comprising: a plurality of concentric annular vertical ribs including a first annular vertical wall and a second annular vertical wall; a first horizontal annular wall connecting the first annular vertical wall to the second annular vertical wall; a seal secured to an upper surface of one of the annular vertical walls or the first horizontal annular wall; and a plurality of radial ribs extending radially outward from the second annular vertical wall. 5) The adjustable plastic manhole grade ring of claim 4 further including a third annular vertical wall connected to the plurality of radial ribs. 6) The adjustable plastic manhole grade ring of claim 5 further including a second horizontal annular wall connecting the second annular vertical wall to the third annular vertical wall. 7) The adjustable manhole grade ring of claim 5 wherein the first horizontal annular wall is a lower wall and the second horizontal annular wall is an upper wall. 8) The adjustable plastic manhole grade ring of claim 4 further including openings through the second annular horizontal wall. 9) The adjustable manhole grade ring of claim 8 wherein the openings also extend through the third annular vertical wall. 10) The adjustable plastic manhole grade ring of claim 4 further including an annular channel for receiving the seal of a similar manhole grade ring stacked therebelow. 11) The adjustable plastic manhole grade ring of claim 10 further including a lip protruding downward from the third annular vertical rib adjacent the channel. 12) A plastic manhole grade ring comprising: a first annular vertical wall and a second annular vertical wall; a first horizontal annular wall connecting the first annular vertical wall to the second annular vertical wall; and a plurality of openings through the first annular vertical wall. 13) The adjustable plastic manhole grade ring of claim 12 further including a plurality of radially extending ribs extending inwardly from the second annular vertical wall and third annular vertical wall connected to the plurality of radial ribs. 14) The adjustable plastic manhole grade ring of claim 13 further including a second horizontal annular wall connecting the second annular vertical wall to the third annular vertical wall. 15) The adjustable manhole grade ring of claim 14 wherein the first horizontal annular wall is an upper wall and the second horizontal annular wall is a lower wall. 16) The adjustable plastic manhole grade ring of claim 12 wherein each opening also extends through the first horizontal annular wall. 17) A plastic manhole grade ring comprising: a first annular vertical wall and a second annular vertical wall; an upper horizontal annular wall extending radially outwardly from the second annular vertical wall; a lower horizontal annular wall extending radially outwardly from the second annular vertical wall, spaced below the upper horizontal annular wall; and a plurality of ribs extending between the second annular vertical wall, the upper horizontal annular wall and the lower horizontal annular wall. 18) The adjustable plastic manhole grade ring of claim 17 further including a third horizontal annular wall connecting the first annular vertical wall to the second annular vertical wall. 19) The adjustable manhole grade ring of claim 17 further including a seal on a first surface of the manhole grade ring for sealing to a similar manhole grade ring stacked therewith. 20) The adjustable manhole grade ring of claim 19 further including a channel formed on a second surface for receiving the seal of the similar manhole grade ring stacked therewith. 21) A form set for a manhole grade ring comprising: a plurality of annular inner forms pivotably mounted to one another about an axis generally transverse to a center axis of each of the inner forms; and an annular outer form, the inner forms also pivotable about the axis relative to the outer form. 22) The form set of claim 21 further including a pair of laterally protruding sections extending outwardly from the outer form. 23) The form set of claim 22 further including a hinge pin connected to the laterally protruding sections and about which the inner forms are pivotably mounted. 24) A form for a manhole grade ring comprising: a base; and an adjustable portion have an adjustable height relative to the base, the adjustable portion having an upper annular wall and an inner annular wall. 25) The form of claim 24 wherein the base includes a generally planar annular inner portion and an annular outer portion having alternating peaks and valleys. 26) The form of claim 25 further including threaded members for adjusting a relative height between the adjustable portion and the base. 27) The form of claim 24 further including a plurality of tapered radial ribs connecting the annular inner portion to the peaks of the annular outer portion. 28) A plastic manhole grade ring comprising: an enclosed body defining an annular cavity; and an opening into the cavity for filling the manhole grade ring with supporting material. 29) The manhole grade ring of claim 28 wherein the manhole grade ring is blow molded or rotationally molded. 